ZHCSCA8A March 2014 – April 2019 TPS65286
PRODUCTION DATA.
Some applications require that an over-current condition disables the part momentarily during a fault condition and re-enables after a pre-set time. This auto-retry functionality can be implemented with external resistors and capacitor shown in Figure 32. During a fault condition, nFAULT pulls low disabling the part. The part is disabled when EN is pulled low, and nFAULT goes high impedance allowing CRETRY1/2 to be charged. The part re-enables when the voltage on EN_SW reaches the turn-on threshold, and the auto-retry time is determined by the resistor/capacitor time constant. The part will continue to cycle in this manner until the fault condition is removed.
Figure 32. Auto Retry Functionality Some applications require auto-retry functionality and the ability to enable/disable with an external logic signal. Figure 33 shows how an external logic signal can drive EN_SW through RFAULT and maintain auto-retry functionality. The resistor/capacitor time constant determines the auto-retry time-out period.
Figure 33. Auto Retry Functionality With External Enable Signal